692
FXUS65 KBYZ 140342
AFDBYZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
942 PM MDT SUN SEP 13 2026
KEY MESSAGES
- BELOW AVERAGE TEMPERATURES THROUGH THE MIDDLE OF THE WEEK.
- CHANCE OF SHOWERS (MAINLY LIGHT) THROUGH MONDAY. ISOLATED
THUNDERSTORMS POSSIBLE IN SOUTHEAST MONTANA THIS EVENING AND
OVERNIGHT, POSSIBLY STRONG.
- COLD FRONT BRINGS BREEZY NORTHWEST WINDS OVERNIGHT. BRISK WEST
WINDS ACROSS THE AREA MONDAY; WIDESPREAD GUSTS OF 30 TO 50 MPH,
STRONGEST FROM BIG TIMBER TO HARLOWTON AND NEAR THE DAKOTAS
BORDER.
DISCUSSION
THROUGH SATURDAY...
AN UPPER LOW CENTERED OVER SOUTHERN WA AND TROUGHING OVER THE
EASTERN US HAS PUT THE AREA UNDER SHORTWAVE RIDGING TODAY. BREEZY
SOUTHEAST WINDS (WIND GUSTS TO 20-45 MPH) WERE FOUND OVER EASTERN
AREAS, WHILE BREEZY SOUTHWEST WINDS (25-50 MPH) WERE FOUND OVER
THE SOUTHWEST MOUNTAINS AND PORTIONS OF THE PARADISE VALLEY. AS
THE LOW LIFTS NORTH AND EAST TONIGHT INTO MONDAY, AN ASSOCIATED
COLD FRONT WILL SWEEP ACROSS THE AREA. ISOLATED TO SCATTERED
SHOWERS AND A FEW THUNDERSTORMS LOOK TO DEVELOP AHEAD OF AND WITH
THE FRONT, THOUGH IN GENERAL, PRECIPITATION AMOUNTS LOOK TO
REMAIN ON THE LIGHT SIDE. SNOW SHOWERS ARE POSSIBLE OVER THE HIGHEST
ELEVATIONS, THOUGH LITTLE IN THE WAY OF ACCUMULATION IS EXPECTED. THERE
REMAINS IS A BRIEF WINDOW OF DECENT CAPE AND SHEAR IN OUR
SOUTHEAST CORNER (CARTER COUNTY) AS THETA-E STREAMS NORTH INTO THE
AREA AHEAD OF THE FRONT. INSTABILITY IS LIMITED, BUT WE COULD SEE
A STRONG STORM OR TWO IN THAT AREA LATE EVENING INTO THE EARLY
OVERNIGHT, AND LATEST CAMS DO SHOW A HELICITY TRACK OR TWO.
BREEZY NORTHWEST WINDS OF 20-40 MPH WILL ACCOMPANY THE FRONT WITH
SHOWERS POTENTIALLY AIDING SOME MIX DOWN WINDS BRINGING LOCALLY
HIGHER GUSTS. HI-RES GUIDANCE CONTINUES TO INDICATE LOCALLY
STRONGER WINDS IN PLACES WITH THE FRONT (RED LODGE AND SHERIDAN).
BEHIND THE FRONT, MONDAY WILL FEATURE DRY, COOLER AND BREEZY
CONDITIONS. HIGHS WILL RANGE FROM THE 60S OVER THE WEST TO THE
LOWER 70S EAST. WIDESPREAD WESTERLY WIND GUSTS OF 30 TO 50 MPH CAN
BE EXPECTED, WITH THE GREATEST WIND GUSTS ALONG THE WESTERN
FOOTHILLS AND OUT EAST NEAR THE DAKOTAS BORDER. LOCATIONS FROM BIG
TIMBER NORTH TO JUDITH GAP HAVE ROUGHLY A 40-70% CHANCE AT SEEING
WIND GUSTS OF 50 MPH OR GREATER, WITH SIMILAR PROBABILITIES NEAR
THE DAKOTAS BORDER. IF WINDS CONTINUE TO TREND HIGHER FOR THE FAR
EAST, A WIND HIGHLITE MAY BE NEEDED, BUT WILL HOLD OFF FOR NOW.
AS WINDS DROP AND SKIES CLEAR OUT MONDAY NIGHT, FROST IS POSSIBLE
(20-40% CHANCE) FOR SOME OF THE COLDER VALLEY LOCATIONS WITH
TEMPERATURES DROPPING INTO THE 30S AND 40S.
ENSEMBLES CONTINUE TO PROG NW TO CYCLONIC FLOW WILL LINGER BEHIND
THE DEPARTING LOW, KEEPING TEMPERATURES A LITTLE COOLER THAN
NORMAL THROUGH MIDWEEK. OCCASIONAL SHORTWAVES MAY BRING A CHANCE
OF LIGHT SHOWERS TO THE AREA AT TIMES, TUESDAY NIGHT/WEDNESDAY AND
LATE WEEK. UNCERTAINTY REMAINS HIGH FOR THE LATTER PART OF THE
WEEK, WITH SOME ENSEMBLE MEMBERS SHOWING THE POTENTIAL FOR A MORE
WIDESPREAD PRECIPITATION EVENT, THOUGH THIS IS SEVERAL DAYS OUT.
HIGHS ARE FORECAST TO RANGE FROM 60S TO LOWER 70S
THROUGH WEDNESDAY. TEMPERATURES IN THE 70S TO NEAR 80 DEGREES ARE
PROGGED FOR THURSDAY, WITH A RETURN TO MORE SEASONABLE
TEMPERATURES (LOWER TO MIDDLE 70S) HEADING INTO THE WEEKEND. WE
MAY SEE LOWS IN THE 30S FOR MONDAY NIGHT/TUESDAY MORNING, WITH
LOWS OTHER NIGHTS MAINLY IN THE 40S TO LOWER 50S THIS WEEK. STP
AVIATION
A DYNAMIC WEATHER SYSTEM MOVING THRU THE NORTHERN ROCKIES WILL BE
ASSOCIATED WITH A PACIFIC COLD FRONTAL PASSAGE OVERNIGHT. THE
FRONT WILL BRING A SHIFT TO GUSTY WESTERLY WINDS. EXPECT GUSTS OF
25-40 KNOTS EARLY, THEN WIDESPREAD MIXED W-NW WINDS OF 30-45 KNOTS
THROUGH THE MONDAY AFTERNOON. HIGHEST GUSTS ARE EXPECTED TO OCCUR
ALONG THE WESTERN FOOTHILLS. WINDS WILL DIMINISH THIS EVENING.
SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE EXPECTED OVERNRIGHT
TO ~15Z. GREATEST POTENTIAL FOR TS IS EAST OF KBIL. SHOWER
ACTIVITY ITSELF MAY PRODUCE LOCAL/BRIEF MVFR, AND ANY
THUNDERSTORMS COULD ENHANCE WIND GUSTS. GUSTY DOWNSLOPE WINDS
BECOME DOMINANT BY MID TO LATE MONDAY MORNING, AND DRY/VFR
CONDITIONS WILL PREVAIL THROUGH THE MONDAY. MOUNTAINS WILL BE
OBSCURED AT TIMES THROUGH EARLY MONDAY.
JKL
PRELIMINARY POINT TEMP/POPS
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 050/069 043/073 047/069 047/077 053/075 051/074 050/077
62/W 00/U 00/U 01/U 45/T 63/W 31/U
LVM 041/064 035/071 040/071 041/078 046/073 044/072 043/075
62/W 00/B 00/U 02/T 55/T 53/T 21/U
HDN 046/071 039/076 042/072 042/080 049/077 046/076 044/078
82/W 00/U 00/U 01/U 35/T 64/T 31/U
MLS 052/070 044/071 050/074 045/079 054/077 050/074 047/076
56/W 00/U 00/U 01/U 36/T 65/W 32/W
4BQ 054/071 044/073 052/076 047/081 055/078 050/074 047/077
32/W 00/U 00/U 12/W 46/T 65/W 32/W
BHK 050/070 041/070 046/078 043/078 050/078 047/073 045/076
45/W 00/B 21/U 02/W 46/T 66/W 43/W
SHR 047/072 036/074 042/072 041/078 047/075 043/072 040/075
32/W 00/U 00/U 12/W 26/T 65/T 22/W
BYZ WATCHES/WARNINGS/ADVISORIES
MT...NONE.
WY...NONE.
WEATHER.GOV/BILLINGS
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